Subversion Repositories HelenOS

Rev

Rev 1839 | Rev 2032 | Go to most recent revision | Blame | Compare with Previous | Last modification | View Log | Download | RSS feed

  1. /*
  2.  * Copyright (C) 2001-2004 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup genericproc
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file
  35.  * @brief   Thread management functions.
  36.  */
  37.  
  38. #include <proc/scheduler.h>
  39. #include <proc/thread.h>
  40. #include <proc/task.h>
  41. #include <proc/uarg.h>
  42. #include <mm/frame.h>
  43. #include <mm/page.h>
  44. #include <arch/asm.h>
  45. #include <arch.h>
  46. #include <synch/synch.h>
  47. #include <synch/spinlock.h>
  48. #include <synch/waitq.h>
  49. #include <synch/rwlock.h>
  50. #include <cpu.h>
  51. #include <func.h>
  52. #include <context.h>
  53. #include <adt/btree.h>
  54. #include <adt/list.h>
  55. #include <typedefs.h>
  56. #include <time/clock.h>
  57. #include <config.h>
  58. #include <arch/interrupt.h>
  59. #include <smp/ipi.h>
  60. #include <arch/faddr.h>
  61. #include <atomic.h>
  62. #include <memstr.h>
  63. #include <print.h>
  64. #include <mm/slab.h>
  65. #include <debug.h>
  66. #include <main/uinit.h>
  67. #include <syscall/copy.h>
  68. #include <errno.h>
  69.  
  70.  
  71. /** Thread states */
  72. char *thread_states[] = {
  73.     "Invalid",
  74.     "Running",
  75.     "Sleeping",
  76.     "Ready",
  77.     "Entering",
  78.     "Exiting",
  79.     "Undead"
  80. };
  81.  
  82. /** Lock protecting the threads_btree B+tree. For locking rules, see declaration thereof. */
  83. SPINLOCK_INITIALIZE(threads_lock);
  84.  
  85. /** B+tree of all threads.
  86.  *
  87.  * When a thread is found in the threads_btree B+tree, it is guaranteed to exist as long
  88.  * as the threads_lock is held.
  89.  */
  90. btree_t threads_btree;     
  91.  
  92. SPINLOCK_INITIALIZE(tidlock);
  93. uint32_t last_tid = 0;
  94.  
  95. static slab_cache_t *thread_slab;
  96. #ifdef ARCH_HAS_FPU
  97. slab_cache_t *fpu_context_slab;
  98. #endif
  99.  
  100. /** Thread wrapper
  101.  *
  102.  * This wrapper is provided to ensure that every thread
  103.  * makes a call to thread_exit() when its implementing
  104.  * function returns.
  105.  *
  106.  * interrupts_disable() is assumed.
  107.  *
  108.  */
  109. static void cushion(void)
  110. {
  111.     void (*f)(void *) = THREAD->thread_code;
  112.     void *arg = THREAD->thread_arg;
  113.  
  114.     /* this is where each thread wakes up after its creation */
  115.     spinlock_unlock(&THREAD->lock);
  116.     interrupts_enable();
  117.  
  118.     f(arg);
  119.     thread_exit();
  120.     /* not reached */
  121. }
  122.  
  123. /** Initialization and allocation for thread_t structure */
  124. static int thr_constructor(void *obj, int kmflags)
  125. {
  126.     thread_t *t = (thread_t *) obj;
  127.  
  128.     spinlock_initialize(&t->lock, "thread_t_lock");
  129.     link_initialize(&t->rq_link);
  130.     link_initialize(&t->wq_link);
  131.     link_initialize(&t->th_link);
  132.  
  133.     /* call the architecture-specific part of the constructor */
  134.     thr_constructor_arch(t);
  135.    
  136. #ifdef ARCH_HAS_FPU
  137. #  ifdef CONFIG_FPU_LAZY
  138.     t->saved_fpu_context = NULL;
  139. #  else
  140.     t->saved_fpu_context = slab_alloc(fpu_context_slab,kmflags);
  141.     if (!t->saved_fpu_context)
  142.         return -1;
  143. #  endif
  144. #endif 
  145.  
  146.     t->kstack = frame_alloc(STACK_FRAMES, FRAME_KA | kmflags);
  147.     if (! t->kstack) {
  148. #ifdef ARCH_HAS_FPU
  149.         if (t->saved_fpu_context)
  150.             slab_free(fpu_context_slab,t->saved_fpu_context);
  151. #endif
  152.         return -1;
  153.     }
  154.  
  155.     return 0;
  156. }
  157.  
  158. /** Destruction of thread_t object */
  159. static int thr_destructor(void *obj)
  160. {
  161.     thread_t *t = (thread_t *) obj;
  162.  
  163.     /* call the architecture-specific part of the destructor */
  164.     thr_destructor_arch(t);
  165.  
  166.     frame_free(KA2PA(t->kstack));
  167. #ifdef ARCH_HAS_FPU
  168.     if (t->saved_fpu_context)
  169.         slab_free(fpu_context_slab,t->saved_fpu_context);
  170. #endif
  171.     return 1; /* One page freed */
  172. }
  173.  
  174. /** Initialize threads
  175.  *
  176.  * Initialize kernel threads support.
  177.  *
  178.  */
  179. void thread_init(void)
  180. {
  181.     THREAD = NULL;
  182.     atomic_set(&nrdy,0);
  183.     thread_slab = slab_cache_create("thread_slab",
  184.                     sizeof(thread_t),0,
  185.                     thr_constructor, thr_destructor, 0);
  186. #ifdef ARCH_HAS_FPU
  187.     fpu_context_slab = slab_cache_create("fpu_slab",
  188.                          sizeof(fpu_context_t),
  189.                          FPU_CONTEXT_ALIGN,
  190.                          NULL, NULL, 0);
  191. #endif
  192.  
  193.     btree_create(&threads_btree);
  194. }
  195.  
  196. /** Make thread ready
  197.  *
  198.  * Switch thread t to the ready state.
  199.  *
  200.  * @param t Thread to make ready.
  201.  *
  202.  */
  203. void thread_ready(thread_t *t)
  204. {
  205.     cpu_t *cpu;
  206.     runq_t *r;
  207.     ipl_t ipl;
  208.     int i, avg;
  209.  
  210.     ipl = interrupts_disable();
  211.  
  212.     spinlock_lock(&t->lock);
  213.  
  214.     ASSERT(! (t->state == Ready));
  215.  
  216.     i = (t->priority < RQ_COUNT -1) ? ++t->priority : t->priority;
  217.    
  218.     cpu = CPU;
  219.     if (t->flags & THREAD_FLAG_WIRED) {
  220.         cpu = t->cpu;
  221.     }
  222.     t->state = Ready;
  223.     spinlock_unlock(&t->lock);
  224.    
  225.     /*
  226.      * Append t to respective ready queue on respective processor.
  227.      */
  228.     r = &cpu->rq[i];
  229.     spinlock_lock(&r->lock);
  230.     list_append(&t->rq_link, &r->rq_head);
  231.     r->n++;
  232.     spinlock_unlock(&r->lock);
  233.  
  234.     atomic_inc(&nrdy);
  235.     avg = atomic_get(&nrdy) / config.cpu_active;
  236.     atomic_inc(&cpu->nrdy);
  237.  
  238.     interrupts_restore(ipl);
  239. }
  240.  
  241. /** Destroy thread memory structure
  242.  *
  243.  * Detach thread from all queues, cpus etc. and destroy it.
  244.  *
  245.  * Assume thread->lock is held!!
  246.  */
  247. void thread_destroy(thread_t *t)
  248. {
  249.     bool destroy_task = false; 
  250.  
  251.     ASSERT(t->state == Exiting || t->state == Undead);
  252.     ASSERT(t->task);
  253.     ASSERT(t->cpu);
  254.  
  255.     spinlock_lock(&t->cpu->lock);
  256.     if(t->cpu->fpu_owner==t)
  257.         t->cpu->fpu_owner=NULL;
  258.     spinlock_unlock(&t->cpu->lock);
  259.  
  260.     spinlock_unlock(&t->lock);
  261.  
  262.     spinlock_lock(&threads_lock);
  263.     btree_remove(&threads_btree, (btree_key_t) ((uintptr_t ) t), NULL);
  264.     spinlock_unlock(&threads_lock);
  265.  
  266.     /*
  267.      * Detach from the containing task.
  268.      */
  269.     spinlock_lock(&t->task->lock);
  270.     list_remove(&t->th_link);
  271.     if (--t->task->refcount == 0) {
  272.         t->task->accept_new_threads = false;
  273.         destroy_task = true;
  274.     }
  275.     spinlock_unlock(&t->task->lock);   
  276.    
  277.     if (destroy_task)
  278.         task_destroy(t->task);
  279.    
  280.     slab_free(thread_slab, t);
  281. }
  282.  
  283. /** Create new thread
  284.  *
  285.  * Create a new thread.
  286.  *
  287.  * @param func  Thread's implementing function.
  288.  * @param arg   Thread's implementing function argument.
  289.  * @param task  Task to which the thread belongs.
  290.  * @param flags Thread flags.
  291.  * @param name  Symbolic name.
  292.  *
  293.  * @return New thread's structure on success, NULL on failure.
  294.  *
  295.  */
  296. thread_t *thread_create(void (* func)(void *), void *arg, task_t *task, int flags, char *name)
  297. {
  298.     thread_t *t;
  299.     ipl_t ipl;
  300.    
  301.     t = (thread_t *) slab_alloc(thread_slab, 0);
  302.     if (!t)
  303.         return NULL;
  304.    
  305.     /* Not needed, but good for debugging */
  306.     memsetb((uintptr_t) t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES, 0);
  307.    
  308.     ipl = interrupts_disable();
  309.     spinlock_lock(&tidlock);
  310.     t->tid = ++last_tid;
  311.     spinlock_unlock(&tidlock);
  312.     interrupts_restore(ipl);
  313.    
  314.     context_save(&t->saved_context);
  315.     context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack, THREAD_STACK_SIZE);
  316.    
  317.     the_initialize((the_t *) t->kstack);
  318.    
  319.     ipl = interrupts_disable();
  320.     t->saved_context.ipl = interrupts_read();
  321.     interrupts_restore(ipl);
  322.    
  323.     memcpy(t->name, name, THREAD_NAME_BUFLEN);
  324.    
  325.     t->thread_code = func;
  326.     t->thread_arg = arg;
  327.     t->ticks = -1;
  328.     t->priority = -1;       /* start in rq[0] */
  329.     t->cpu = NULL;
  330.     t->flags = flags;
  331.     t->state = Entering;
  332.     t->call_me = NULL;
  333.     t->call_me_with = NULL;
  334.    
  335.     timeout_initialize(&t->sleep_timeout);
  336.     t->sleep_interruptible = false;
  337.     t->sleep_queue = NULL;
  338.     t->timeout_pending = 0;
  339.  
  340.     t->in_copy_from_uspace = false;
  341.     t->in_copy_to_uspace = false;
  342.  
  343.     t->interrupted = false;
  344.     t->join_type = None;
  345.     t->detached = false;
  346.     waitq_initialize(&t->join_wq);
  347.    
  348.     t->rwlock_holder_type = RWLOCK_NONE;
  349.        
  350.     t->task = task;
  351.    
  352.     t->fpu_context_exists = 0;
  353.     t->fpu_context_engaged = 0;
  354.  
  355.     thread_create_arch(t);      /* might depend on previous initialization */
  356.    
  357.     /*
  358.      * Attach to the containing task.
  359.      */
  360.     ipl = interrupts_disable();  
  361.     spinlock_lock(&task->lock);
  362.     if (!task->accept_new_threads) {
  363.         spinlock_unlock(&task->lock);
  364.         slab_free(thread_slab, t);
  365.         interrupts_restore(ipl);
  366.         return NULL;
  367.     }
  368.     list_append(&t->th_link, &task->th_head);
  369.     if (task->refcount++ == 0)
  370.         task->main_thread = t;
  371.     spinlock_unlock(&task->lock);
  372.  
  373.     /*
  374.      * Register this thread in the system-wide list.
  375.      */
  376.     spinlock_lock(&threads_lock);
  377.     btree_insert(&threads_btree, (btree_key_t) ((uintptr_t) t), (void *) t, NULL);
  378.     spinlock_unlock(&threads_lock);
  379.    
  380.     interrupts_restore(ipl);
  381.    
  382.     return t;
  383. }
  384.  
  385. /** Terminate thread.
  386.  *
  387.  * End current thread execution and switch it to the exiting
  388.  * state. All pending timeouts are executed.
  389.  *
  390.  */
  391. void thread_exit(void)
  392. {
  393.     ipl_t ipl;
  394.  
  395. restart:
  396.     ipl = interrupts_disable();
  397.     spinlock_lock(&THREAD->lock);
  398.     if (THREAD->timeout_pending) { /* busy waiting for timeouts in progress */
  399.         spinlock_unlock(&THREAD->lock);
  400.         interrupts_restore(ipl);
  401.         goto restart;
  402.     }
  403.     THREAD->state = Exiting;
  404.     spinlock_unlock(&THREAD->lock);
  405.     scheduler();
  406.  
  407.     /* Not reached */
  408.     while (1)
  409.         ;
  410. }
  411.  
  412.  
  413. /** Thread sleep
  414.  *
  415.  * Suspend execution of the current thread.
  416.  *
  417.  * @param sec Number of seconds to sleep.
  418.  *
  419.  */
  420. void thread_sleep(uint32_t sec)
  421. {
  422.     thread_usleep(sec*1000000);
  423. }
  424.  
  425. /** Wait for another thread to exit.
  426.  *
  427.  * @param t Thread to join on exit.
  428.  * @param usec Timeout in microseconds.
  429.  * @param flags Mode of operation.
  430.  *
  431.  * @return An error code from errno.h or an error code from synch.h.
  432.  */
  433. int thread_join_timeout(thread_t *t, uint32_t usec, int flags)
  434. {
  435.     ipl_t ipl;
  436.     int rc;
  437.  
  438.     if (t == THREAD)
  439.         return EINVAL;
  440.  
  441.     /*
  442.      * Since thread join can only be called once on an undetached thread,
  443.      * the thread pointer is guaranteed to be still valid.
  444.      */
  445.    
  446.     ipl = interrupts_disable();
  447.     spinlock_lock(&t->lock);
  448.     ASSERT(!t->detached);
  449.     spinlock_unlock(&t->lock);
  450.     interrupts_restore(ipl);
  451.    
  452.     rc = waitq_sleep_timeout(&t->join_wq, usec, flags);
  453.    
  454.     return rc; 
  455. }
  456.  
  457. /** Detach thread.
  458.  *
  459.  * Mark the thread as detached, if the thread is already in the Undead state,
  460.  * deallocate its resources.
  461.  *
  462.  * @param t Thread to be detached.
  463.  */
  464. void thread_detach(thread_t *t)
  465. {
  466.     ipl_t ipl;
  467.  
  468.     /*
  469.      * Since the thread is expected to not be already detached,
  470.      * pointer to it must be still valid.
  471.      */
  472.     ipl = interrupts_disable();
  473.     spinlock_lock(&t->lock);
  474.     ASSERT(!t->detached);
  475.     if (t->state == Undead) {
  476.         thread_destroy(t);  /* unlocks &t->lock */
  477.         interrupts_restore(ipl);
  478.         return;
  479.     } else {
  480.         t->detached = true;
  481.     }
  482.     spinlock_unlock(&t->lock);
  483.     interrupts_restore(ipl);
  484. }
  485.  
  486. /** Thread usleep
  487.  *
  488.  * Suspend execution of the current thread.
  489.  *
  490.  * @param usec Number of microseconds to sleep.
  491.  *
  492.  */
  493. void thread_usleep(uint32_t usec)
  494. {
  495.     waitq_t wq;
  496.                  
  497.     waitq_initialize(&wq);
  498.  
  499.     (void) waitq_sleep_timeout(&wq, usec, SYNCH_FLAGS_NON_BLOCKING);
  500. }
  501.  
  502. /** Register thread out-of-context invocation
  503.  *
  504.  * Register a function and its argument to be executed
  505.  * on next context switch to the current thread.
  506.  *
  507.  * @param call_me      Out-of-context function.
  508.  * @param call_me_with Out-of-context function argument.
  509.  *
  510.  */
  511. void thread_register_call_me(void (* call_me)(void *), void *call_me_with)
  512. {
  513.     ipl_t ipl;
  514.    
  515.     ipl = interrupts_disable();
  516.     spinlock_lock(&THREAD->lock);
  517.     THREAD->call_me = call_me;
  518.     THREAD->call_me_with = call_me_with;
  519.     spinlock_unlock(&THREAD->lock);
  520.     interrupts_restore(ipl);
  521. }
  522.  
  523. /** Print list of threads debug info */
  524. void thread_print_list(void)
  525. {
  526.     link_t *cur;
  527.     ipl_t ipl;
  528.    
  529.     /* Messing with thread structures, avoid deadlock */
  530.     ipl = interrupts_disable();
  531.     spinlock_lock(&threads_lock);
  532.  
  533.     for (cur = threads_btree.leaf_head.next; cur != &threads_btree.leaf_head; cur = cur->next) {
  534.         btree_node_t *node;
  535.         int i;
  536.  
  537.         node = list_get_instance(cur, btree_node_t, leaf_link);
  538.         for (i = 0; i < node->keys; i++) {
  539.             thread_t *t;
  540.        
  541.             t = (thread_t *) node->value[i];
  542.             printf("%s: address=%#zx, tid=%zd, state=%s, task=%#zx, context=%ld, code=%#zx, stack=%#zx, cpu=",
  543.                 t->name, t, t->tid, thread_states[t->state], t->task, t->task->context, t->thread_code, t->kstack);
  544.             if (t->cpu)
  545.                 printf("cpu%zd", t->cpu->id);
  546.             else
  547.                 printf("none");
  548.             if (t->state == Sleeping) {
  549.                 printf(", kst=%#zx", t->kstack);
  550.                 printf(", wq=%#zx", t->sleep_queue);
  551.             }
  552.             printf("\n");
  553.         }
  554.     }
  555.  
  556.     spinlock_unlock(&threads_lock);
  557.     interrupts_restore(ipl);
  558. }
  559.  
  560. /** Check whether thread exists.
  561.  *
  562.  * Note that threads_lock must be already held and
  563.  * interrupts must be already disabled.
  564.  *
  565.  * @param t Pointer to thread.
  566.  *
  567.  * @return True if thread t is known to the system, false otherwise.
  568.  */
  569. bool thread_exists(thread_t *t)
  570. {
  571.     btree_node_t *leaf;
  572.    
  573.     return btree_search(&threads_btree, (btree_key_t) ((uintptr_t) t), &leaf) != NULL;
  574. }
  575.  
  576. /** Process syscall to create new thread.
  577.  *
  578.  */
  579. unative_t sys_thread_create(uspace_arg_t *uspace_uarg, char *uspace_name)
  580. {
  581.     thread_t *t;
  582.     char namebuf[THREAD_NAME_BUFLEN];
  583.     uspace_arg_t *kernel_uarg;
  584.     uint32_t tid;
  585.     int rc;
  586.  
  587.     rc = copy_from_uspace(namebuf, uspace_name, THREAD_NAME_BUFLEN);
  588.     if (rc != 0)
  589.         return (unative_t) rc;
  590.  
  591.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  592.     rc = copy_from_uspace(kernel_uarg, uspace_uarg, sizeof(uspace_arg_t));
  593.     if (rc != 0) {
  594.         free(kernel_uarg);
  595.         return (unative_t) rc;
  596.     }
  597.  
  598.     if ((t = thread_create(uinit, kernel_uarg, TASK, THREAD_FLAG_USPACE, namebuf))) {
  599.         tid = t->tid;
  600.         thread_ready(t);
  601.         return (unative_t) tid;
  602.     } else {
  603.         free(kernel_uarg);
  604.     }
  605.  
  606.     return (unative_t) ENOMEM;
  607. }
  608.  
  609. /** Process syscall to terminate thread.
  610.  *
  611.  */
  612. unative_t sys_thread_exit(int uspace_status)
  613. {
  614.     thread_exit();
  615.     /* Unreachable */
  616.     return 0;
  617. }
  618.  
  619. /** @}
  620.  */
  621.